Conveyor installation with transport containers

ABSTRACT

A conveyor installation with transport containers guided at a rail and each of which can be propelled by means of its own drive unit. Each of the transport containers is supported at the associated rail through the agency of a respective pair of travelling wheels arranged in the direction of the transverse axis of the transport container and by means of guide wheels arranged in the lengthwise axis of the transport container.

United States Patent 1191 Kastenbein 1451 Sept. 10, 1974 CONVEYORINSTALLATION WITH TRANSPORT CONTAINERS [75] Inventor: Werner Kastenbein,Zurich,

Switzerland [73] Assignee: Hans lngold & C0., Zollikon, Switzerland [22]Filed: Jan. 10, 1973 [21] App]. No.: 322,363

[30] Foreign Application Priority Data Jan. 14, 1972 Switzerland 493/7252 US. Cl ..l04/246,104/243, 105/75 51 1111.0 B61f 13/00 [58] Field ofSearch 104/242, 243, 245, 246; 105/75, 73; 280/43.1, 47.16, 110, 43.12;

ISO/24.02

[56] References Cited UNITED STATES PATENTS 682,662 9/1901 Bartholomew280/47.16 1,373,754 4/1921 Miller 104/246 1,613,866 1/1927 Avery 104/2421,682,974 9/1928 Lukens 104/242 2,943,865 7/1960 Fite ISO/24.02

FOREIGN PATENTS OR APPLICATIONS 920,189 11/1954 Germany 104/243 PrimaryExaminerRobert J. Spar Assistant Examiner-Kenneth Noland Attorney,Agent, or Firm1-li1l, Gross, Simpson, Van Santen, Steadman, Chiara &Simpson [5 7] ABSTRACT A conveyor installation with transport containersguided at a rail and each of which can be propelled by means of its owndrive unit. Each of the transport containers is supported at theassociated rail through the agency of a respective pair of travellingwheels arranged in the direction of the transverse axis of the transportcontainer and by means of guide wheels arranged in the lengthwise axisof the transport container.

13 Claims, 3 Drawing Figures CONVEYOR INSTALLATION WITH TRANSPORTCONTAINERS BACKGROUND OF THE INVENTION The present invention relates toa new and improved construction of conveyor installation incorporatingtransport containers which are guided at a rail or track and each ofwhich can be propelled by means of its own drive unit.

With known conveyor installations of this type, as a general rule thetransport containers are guided and supported at the rail by means ofpairs of wheels, that is to say, by means of wheels arranged in pairs atthe same axle. With this type of construction, the mutuallycontradictory requirements for realizing a sufficient stability, on theone hand, and small radius of the curves of the rails, on the otherhand, can also not be readily completely satisfied, only by submittingto certain compromises. Thus, the wide track gauge which is desired fromthe standpoint of attaining the maximum possible stability precludes theuse of narrow curves of the rails, especially then when there are beinghandled larger size containers, the center of gravity of which islocated relatively high above the rail and the stability of which aboutthe transverse axis requires a relatively long wheel spacing. In mostcases it is not possible, for constructional reasons, to maintain assmall as possible curve radius, since the friction which arises duringtravelling through the relevant curves requires a considerable driveoutput and hence necessitates the use of expensive and heavy driveunits. 1

SUMMARY OF THE INVENTION Hence it is a primary object of the presentinvention to provide an improved construction of conveyor installationequipped with transport containers which effectively and reliablyovercomes the aforementioned drawbacks and limitations of the prior artproposals.

Now in order to overcome the aforementioned drawbacks and to fulfill theobjective indicated above as well as others which will become morereadily apparent as the description proceeds, the conveyor installationof this development is manifested by the features that each of thetransport containers is supported at the associated rail by means of apair of travelling wheels arranged along the transverse axis of thetransport container and by means of a pair of guide wheels arrangedalong the lengthwise axis of the transport container.

BRIEF DESCRIPTION OF THE DRAWING The invention will be better understoodand objects other than those set forth above, will become apparent whenconsideration is given to the following detailed description thereof.Such description makes reference to the annexed drawing wherein:

FIG. 1 schematically illustrates in side view the travelling carriage ofa transport container according to the invention;

FIG. 2 is a sectional view of the carriage depicted in FIG. 1, takensubstantially along the line lI-II thereof; and

FIG. 3 is a sectional view of the arrangement of FIG. 1, takensubstantially along the line III-III thereof, and additionally showing across-section of the associated rail and schematically indicating thetransport container which is placed upon the travelling carriage.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Considering now theillustrated exemplary embodiment, it will be understood that thetravelling carriage, generally designated by reference character 1,possesses a travelling wheel 2 which is located at each side of thetravelling carriage 1 along the transverse axis thereof as well as arespective guide wheel 3 which is located at each end of such carriageand which is arranged at the lengthwise or longitudinally extending axisof such carriage. A balance beam or rocker 5 which is hingedly connectedby means of a pivot shaft 4 to the carriage 1 carries a drive unit 6equipped with a drive wheel 7. This drive wheel 7 is coaxially arrangedwith respect to the transverse axis and laterally offset with respect tothe lengthwise axis of the carriage 1. Further, drive wheel 7, as bestseen by referring to FIG. 3, frictionally engages at the central orintermediate flange or web 12 of a track or rail member 9 possessing asubstantially C-shaped cross-sectional configuration. In order toincrease the friction inherently brought about by the weight of thedrive unit 6, there is advantageously provided a resilient element, herein the form of a blade spring 8 (FIG. 1) which is anchored at its oneend at location 9 at the carriage l and engages at its other end withthe upper surface of the drive unit 6. The degree of pivotability of thedrive unit 6 and the balance beam or rocker 5 which carries such driveunit 6 and which is subjected to the action of its own weight and thespring force can be adjustably limited by a stop screw 10. Asschematically indicated in FIG. 3, the carriage 1 carries a container 11 which is secured to its top surface.

The lateral guiding of the carriage l in the rail 9 of C-shapedcross-section is insured for by suitable sliding bodies or guidingelement means 30 formed of a material poor in friction, preferablyplastic, mounted at the side walls of the carriage at the terminal orend regions thereof, and which cooperate with the lateral flanges 13 ofthe rail 9. The lateral flanges 13 of the rail 9 have inwardly directedmarginal border or ledges 14 which engage over the travelling wheels 2of the carriage 1 in order to guide such in the rail 9 in the verticaldirection.

With the container 11 completely loaded, the carriage 1 bears by meansof its four wheels, that is to say, by means of the pair of travellingwheels 2 and both of the guide wheels 3 at the central web 12 of therail 9, wherein however the loading of the wheels 2 differs from oneanother since owing to the contact force of the friction wheel 7 at therail, the travelling wheel 2 which is located at the region thereof (inFIG. 2 the lower situated travelling wheel) is considerably relieved ofload, particularly then when such contact force is chosen to berelatively great in consideration of the desire to insure for theself-travelling capability of relatively large and thereforecorrespondingly loaded containers. Consequently, there occurs a certainrelieving of the load acting upon both of the guide wheels 3, even ifsuch is slight, or at least one such wheel. The correspondingrelationships can be better understood if it is imagined that thecontainer is empty or only partially loaded to such an extent that theforce of the spring 8 is sufficient to raise the travelling wheel 2neighboring the friction wheel 7 from the rail until such, as the casemay be, bears against the marginal border or ledge 14 of the railsituated over such wheel. As a result, the carriage tilts about itstransverse axis, which is now slightly inclined, and bears upon only oneof both guide wheels 3. There is therefore produced a three-pointsupport, especially by means of the friction wheel 7, the travellingwheel 2 remote therefrom, and a guide wheel 3, which as a general ruleis the guide wheel which is located rearwardly in the direction oftravel. Starting from this readily imaginable position, it should bereadily understood that such three-point support also is maintained ifthe container is fully loaded, since, as already mentioned, the frictionwheel, the travelling wheel 2 remote therefrom, and one of the guidewheels 3, also then will support at the rail the essential part of theweight of the transport container and the actual load when the secondtravelling wheel and- /or guide wheel contacts the travelling web 12 ofthe rail 9. Owing to the foregoing considerations, the support of thetransport container upon the rail is especially stable, and specificallyalso then when the travelling web 12 of the rail exhibits irregularitiesor distorted or twisted portions. Accordingly, the rail and its mountingcan be designed much easier and generally adjustments thereof can becarried out under much less stringent requirements. On the other hand,the carriage itself will be less subjected to the load or stress of atwisted portion of the rail, something which likewise provides forconstructional similification of the system. Finally, the frictionconditions generally, especially however in curves, are more favorable,so that in consideration thereof practically no limitations are imposedupon a reduction of the radius of the curves. Of course, the holdingability of the carriage in the curves of the track system is alreadyquite good owing to the described arrangement of the travelling wheelsand guide wheels and is particularly then considerable if the curveradius is undertoken as a function of the track gauge. The incrasedsteerability of the carriage which is inherently brought about by thewheel arrangement and also by the three-point support, also has theeffect that the gliding bodies, which have the task of carrying out thelateral guiding of the carriage at the rail, are only slightly loaded inthe curves as well as along the straight track sections. Such glidingbodies can be replaced by guide rolls or even completely omitted ifthere is provided for the guidewheels a guide track, as schematicallyindicated at 40 in FIG. 3. For this purpose, there could be used, forinstance, the current rail which has not been particularly illustratedin the drawing, and which in a practical construction of the equipment,would be arranged at the intermediate travelling web 12 of the rail 9and would transmit the driving energy for the drive unit 6 through theagency of nonillustrated sliding contacts or equivalent structure.

It should be understood that the friction wheel 7 can be shifted more orless in offset relationship to one or the other side with respect to thelengthwise center line of the carriage. Application of the frictionwheel 7 against the travelling web 12 of the rail 9 could of courseoccur in a different manner than through the use of a resilient spring,such as the depicted blade spring; for instance it could occur incertain cases through the use of a mechanical, hydraulic, pneumatic,electrical, direct or indirect (for instance through the use of aspindle) operating contacting or applying means.

While there is shown and described present preferred embodiments of theinvention, it is to be distinctly understood that the invention is notlimited thereto but may be otherwise variously embodied and practicedwithin the scope of the following claims. ACCORD- INGLY,

What is claimed is:

l. A conveyor installation comprising at least one transport container,a rail for guiding said transport container for movement therealong,said transport container having its own drive unit for propelling thetransport container along the rail, said transport container having atransversely extending axis and a lengthwise extending axis, a pair ofmain load supporting traveling wheels arranged on the transverselyextending axis and a pair of guide wheels arranged on the lengthwiseextending axis at least one of said guide wheels lying remote from andto each side of said transversely extending axis, said transportcontainer being supported by said wheels at said rail, the drive unitincorporating a drive wheel positioned intermediate the gauge of thepair of traveling wheels, the drive wheel downwardly shiftable relativeto the pair of traveling wheels independently thereof.

2. The conveyor installation as defined in claim 1, further includingguide element means for guiding the transport container at the rail andengaging with the latter.

3. The conveyor installation as defined in claim 2, wherein said railpossesses a guide track for the guide wheels.

4. The conveyor installation as defined in claim 1, further includingmeans for placing said drive wheel in contact with the rail and engagingfrom above with said drive wheel.

5. The conveyor installation as defined in claim 4, wherein said placingmeans comprises a spring.

6. The conveyor installation as defined in claim 5, further including aguide ledge extending along the rail and at least above the travellingwheel which neighbors the drive wheel.

7. The conveyor installation as defined in claim 6, wherein said railpossesses a configuration in crosssection which substantiallyapproximates the shape of a substantially sharp cornered C.

8. The conveyor installation as defined in claim 7, wherein said railincludes a web portion, said drive wheel engaging with said web portion.

9. The conveyor installation as defined in claim 8, wherein the drivewheel is a friction wheel.

10. The conveyor installation as defined in claim 2, wherein the railincludes vertically extending guide surfaces and the guide element meansare located adjacent the front and rear endsof the carriage on oppositesides thereof and project therefrom for engagement with vertical guidesurfaces.

11. The conveyor installation of claim 1, wherein the drive unitincludes means for rotating a drive wheel, the drive wheel and the meansfor rotating the drive wheel being attached to a common frame member,the common frame member being pivotably hinged to the transportcontainer whereby the combined weight of the drive wheel and the drivingmeans bias the drive wheel downwardly.

12. The conveyor installation of claim 11, wherein additional biasingmeans are provided effective to bias the drive unit downwardly relativeto the pair of traveldrive wheel is positioned offset from thelengthwise extending axis and has a diameter greater than the travellingwheel.

1. A conveyor installation comprising at least one transport container,a rail for guiding said transport container for movement therealong,said transport container having its own drive unit for propelling thetransport container along the rail, said transport container having atransversely extending axis and a lengthwise extending axis, a pair ofmain load supporting traveling wheels arranged on the transverselyexTending axis and a pair of guide wheels arranged on the lengthwiseextending axis at least one of said guide wheels lying remote from andto each side of said transversely extending axis, said transportcontainer being supported by said wheels at said rail, the drive unitincorporating a drive wheel positioned intermediate the gauge of thepair of traveling wheels, the drive wheel downwardly shiftable relativeto the pair of traveling wheels independently thereof.
 2. The conveyorinstallation as defined in claim 1, further including guide elementmeans for guiding the transport container at the rail and engaging withthe latter.
 3. The conveyor installation as defined in claim 2, whereinsaid rail possesses a guide track for the guide wheels.
 4. The conveyorinstallation as defined in claim 1, further including means for placingsaid drive wheel in contact with the rail and engaging from above withsaid drive wheel.
 5. The conveyor installation as defined in claim 4,wherein said placing means comprises a spring.
 6. The conveyorinstallation as defined in claim 5, further including a guide ledgeextending along the rail and at least above the travelling wheel whichneighbors the drive wheel.
 7. The conveyor installation as defined inclaim 6, wherein said rail possesses a configuration in cross-sectionwhich substantially approximates the shape of a substantially sharpcornered C.
 8. The conveyor installation as defined in claim 7, whereinsaid rail includes a web portion, said drive wheel engaging with saidweb portion.
 9. The conveyor installation as defined in claim 8, whereinthe drive wheel is a friction wheel.
 10. The conveyor installation asdefined in claim 2, wherein the rail includes vertically extending guidesurfaces and the guide element means are located adjacent the front andrear ends of the carriage on opposite sides thereof and projecttherefrom for engagement with vertical guide surfaces.
 11. The conveyorinstallation of claim 1, wherein the drive unit includes means forrotating a drive wheel, the drive wheel and the means for rotating thedrive wheel being attached to a common frame member, the common framemember being pivotably hinged to the transport container whereby thecombined weight of the drive wheel and the driving means bias the drivewheel downwardly.
 12. The conveyor installation of claim 11, whereinadditional biasing means are provided effective to bias the drive unitdownwardly relative to the pair of traveling wheels, the biasing forceincluding the additional biasing means and the weight of the drive unitexceeding the weight of the transport container when the transportcontainer is empty.
 13. The conveyor installation of claim 1, whereinthe drive wheel is positioned offset from the lengthwise extending axisand has a diameter greater than the travelling wheel.